VCE IT Theory Slideshows by Mark Kelly study design By Mark Kelly, vceit.com, Begin

Contents Searching, queries, finds Sorting Filtering 2

Queries / Finds Called 'finding' in Filemaker, a RDBMS can perform powerful searches using AND and OR logic, often using Query By Example where the desired data is entered into the field(s) where it should be found. 3VCE IT slideshows © Mark Kelly, vceit.com

Filemaker and Access allow similar search techniques. In the search below, the RDBMS will find all records of people who have a surname starting with G and an age less than 17. Note that search terms in the same row are ANDed. More powerful searches can be easily built... 4VCE IT slideshows © Mark Kelly, vceit.com SurnameAge G*<17

In this example, three search terms are used. The DBMS will now find records of... – All people whose Surname begins with 'G' AND Age is less than 17 – OR All people whose surname begins with K and ends with G AND have an age of 16 or more – OR All people whose age is less than 5. 5VCE IT slideshows © Mark Kelly, vceit.com SurnameAge G*<17 K*G>=16 <5

Notice how each new row of criteria is OR'ed with the other rows, so the records found by each row are all included. 6VCE IT slideshows © Mark Kelly, vceit.com SurnameAge G*<17 K*G>=16 <5

A simple search (often triggered by CTRL+F) lets you find text or data in databases, spreadsheets, text documents. 7VCE IT slideshows © Mark Kelly, vceit.com

Some searches let you search multiple documents at once (sometimes called grep). More powerful tools let you use regular expressions that act like wildcards in search terms to find variants of the text being hunted. – e.g. ‘colour’, ‘color’, ‘colouring’, ‘coloured’ ‘colourful’ 8VCE IT slideshows © Mark Kelly, vceit.com

Since some searches (queries, finds) are frequently used (e.g. video rental customers whose DVD is overdue for return), searches can be stored for later reuse. This makes multi-step searches quick and simple even for inexperienced database users. 9VCE IT slideshows © Mark Kelly, vceit.com

Sorting is usually performed before producing output to organise data into an order where it's easy to find values (e.g. a name in a long list) or significant records (e.g. the ones with extraordinary values, such as the biggest or smallest). RDBMS can sort by several fields in a hierarchical way. e.g. by SURNAME, then by FIRSTNAME, then by MIDDLEINITIAL. 10VCE IT slideshows © Mark Kelly, vceit.com

The most important field (surname) is sorted first; Where surnames are the same, those records are sorted by first name; Where surnames and firstnames are the same, records are then sorted by middle initial. 11VCE IT slideshows © Mark Kelly, vceit.com

12VCE IT slideshows © Mark Kelly, vceit.com Data can be sorted differently depending on what the user needs to find. For example, a database programmer might sort records by ID, but office workers may need the same records sorted by name.

Users can specify what records to show by indicating what contents they're looking for. In Access. 13VCE IT slideshows © Mark Kelly, vceit.com

Filtering in Excel 14VCE IT slideshows © Mark Kelly, vceit.com

Mark Kelly vceit.com These slideshows may be freely used, modified or distributed by teachers and students anywhere but they may NOT be sold. they must NOT be redistributed if you modify them. This is not a VCAA publication and does not speak for VCAA. Portions (e.g. exam questions, study design extracts, glossary terms) may be copyright Victorian Curriculum and Assessment Authority and are used with permission for educational purposes. Thanks, guys! VCE IT THEORY SLIDESHOWS study design 15 VCE IT slideshows © Mark Kelly, vceit.com